Two-speed take-up drive for camera

ABSTRACT

A unidirectional take-up drive mechanism of a camera of the type which accepts a film-loaded cartridge is provided with a pair of movable gears mounted on a pivoted lever whereby the gears can be moved into or out of meshing engagement with another pair of gears that drive the cartridge take-up in normal filming operation. The first pair of gears change the gear ratio of the take-up drive mechanism to slow down the rotation of the cartridge take-up so that it does not wind the film as fast as the film is fed from the cartridge supply, thereby creating an excess of loosely wound film in the cartridge. The excess film is rewound onto the supply, which film may be exposed a second time during a lap dissolve sequence.

United States Patent 1151 3,680,813 Koeber 1451 Aug. 1, 1972 [54]TWO-SPEED TAKE-UP DRIVE FOR CAMERA Primary ExaminerLeonard D. ChristianAtt0rneyWilliam F. Pinsak, John E. Peele, .lr., Ken- [72] Inventor.Henry J. Koeber, Deerfield, Ill. neth w. Greb and William K. Serp [73]Assignee: Bell & Howell Company, Chicago,

111. [57] ABSTRACT [22] Filed: July 2, 1970 A unidirectional take-updrive mechanism of a camera of the type which accepts a film-loadedcartridge is [211 App]' SL871 provided with a pair of movable gearsmounted on a pivoted lever whereby the gears can be moved into or 52 US.Cl ..242/205, 352/91 out of meshing engagement with another P of gears51 Int. Cl. ..G03b 1/04 that drive the Cartridge take-up in normalfilming [58] Field of Search ..242/197-210; Operation The first P ofgears change the s ratio 74/194 2O0. 352/168 180482 91 217 of thetake-up drive mechanism to slow down the rotav tion of the cartridgetake-up so that it does not wind [56] References Cited the film as fastas the film is fed from the cartridge supply, thereby creating an excessof loosely wound UNITED STATES PATENTS film in the cartridge. The excessfilm is rewound onto the supply, which film may be exposed a second time3,352,169 11/1967 Delm et a1. ..74/194 1,468,091 9/1923 Thalhammer..352/91 durmg a lap dlssolve Sequence 3,425,776 2/1969 Mayr et al..352/91 X 8 Claims, 2 Drawing Figures 1 TWO-SPEED TAKE-UP DRIVE FORCAMERA This invention relates to means for making a lap dissolve with acamera having a cartridge take-up driveable in only one direction, andis particularly concerned with means for changing the gear ratio of atake-up relative to the speed at which the film is transported from thesupply in the cartridge.

Lap dissolves are made by fading out one image by gradually reducing theexposure of the film and then fading in a new image on the same portionof the film by exposing it a second time and gradually increasing theexposure until the proper exposure is reached. Although this sequence ofoperation is a conventional photographic technique with cameras in whichthe take-up reel can be reversed to rewind the partially exposed film onthe supply reel, it is difficult to make a lap dissolve with cameras inwhich the take-up can be rotated in only one direction.

The R. Bosch Elektronik & Photokino German Pat. No. 1,286,894, disclosesa mechanism for making a lap dissolve with a camera of the typementioned above, but the mechanism is complicated and cumbersome tooperate. The structure of the German patent includes a manually operableblocking member to stop the takeup reel, a manually disengageableclutch, and a selectively controllable claw that controls the directionof the film travel. It is necessary to disengage the clutch and engagethe blocking member to allow the once exposed film to store itselfloosely in the cartridge. After the exposed film is rewound on thesupply reel, it is necessary to disengage the blocking member, engagethe clutch, and move the claw back to its initial position, before thenormal operation of the camera can be resumed.

1n the present structure, a single lever is pivoted to interpose atransmission in the gear train of the take-up drive mechanism thatnormally drives the camera and the take-up of the cartridge. Thetransmission changes the gear ratio of the take-up drive, and therebyslows the rotation of the take-up to cause an excess of partiallyexposed film to buildup in the cartridge so that the film may be rewoundand a lap dissolve can be made. The lever is shifted back to itsoriginal position when the normal operation of the camera is to beresumed.

Suitable structure by means of which the above mentioned and otheradvantages of the invention are attained will be fully described in thefollowing specification, taken in conjunction with the accompanyingdrawings showing a preferred embodiment of the invention.

In the drawings:

FIG. 1 is a perspective view of a drive mechanism embodying theinvention, with portions broken away to facilitate illustration, and

FIG. 2 is a side elevational view of the drive mechanism on a reducedscale.

Referring to the drawings, a housing 11 has a partition 12 defining onewall of a cartridge chamber 13 at one side of the housing. A cartridge14, positioned in chamber 13, encloses a take-up, shown as hub 15, forreceiving film from supply 15' when the camera is operated. The hub hasa cylindrical wall 16 that fits within an opening 17 in the wall of thecartridge adjacent the partition. The partition 12 has an opening 18 inregistration with the opening 17. A bearing 19 is mounted in the opening18.

A take-up driver 20 comprises a shaft 21 rotatably mounted in thebearing 19 and a plate 22 fixed to the shaft and fitted within thecylindrical wall 16. The plate 22 has fingers 23 engaging the take-uphub to rotate it as the shaft 21 is rotated. A gear 24 is fixed to theend of shaft 21 remote from the plate 22. A compound gear 25, comprisinga pinion gear 26 and a larger gear 27, is rotatably mounted on the shaft21 between the gear 24 and the bearing 19. A thrust washer 28 is mountedon the shaft 21 between gear 27 and the bearing 19. A spring washer 29fixed on the shaft 21 between the gears 24 and 27 frictionally engagesboth of these gears. During normal filming operations, the compound gear25 is rotated, by means hereinafter described, and the gear 24 is drivenby the friction exerted thereagainst by the spring washer 29. This drivemechanism drives the take-up at the same rate as film is withdrawn fromthe supply so that the film fed from the supply through the camera isrewound on the take-up without any slack. That is, a length of filmequal to that taken-up is transported from the supply by the camerashuttle or claw (not shown).

The means for driving the compound gear 25 comprises two continuallymeshed gears 30 and 31. Gear 30 is rotatably mounted on pin 32, which isfixed to the partition 12 and projects into the mechanism chamber of thecamera in parallel relationship to the shaft 21. Gear 30 is in meshingengagement with gear 27, and during normal filming operation drives thatgear when gear 31 is driven by a motor 33 which in this preferredembodiment simultaneously drives the film transport claw. The resultinggear ratio causes the take-up hub 15 to wind up the same length of filmas is fed by the claw.

A lever 34 is pivotally mounted at one end on a pin 35 projecting fromthe partition 12 in the same direction as the shaft 21. A controlmember, shown as rod 36, coupled to lever 34 intermediate its length,projects externally through a wall of the housing 11, shown as top wall37. The rod is provided with a button 38 which may be pressed downwardlyto move the lever pivotally in one direction. A tension spring 39 issecured to the wall 37 and to the lever to retract the lever when thepressure against the button 38 is released. A pair of gears fixedtogether for co-rotation, comprises a pinion gear 41 and another gear42, mounted on a stub shaft 43 extending through the end portion oflever 34. In the preferred embodiment, the gear pair is fixed to stubshaft 43, which shaft is rotatably mounted on the lever.

Gears 41 and 42 are so located that when the lever 34 is moved pivotallyby downward pressure on the button 38, the gears move into meshingengagement with the gears 24 and 26, respectively. When the gears 41 and42 are interposed in the gear train that drives the take-up hub duringthe normal filming operation, they eliminate the effect of thefrictional pressure of the spring washer 29 on the gear 24. The piniongear 26, which is driven through gear 27 by gear 30, drives gear 42, andthereby drives pinion gear 41 which provides a positive gear drive forthe gear 24. Thrust washer 28 and the spring washer 29 permit the shaft21 to rotate independently of the friction between the spring washer 29and the gear 24. By interposition of gears 41 and 42 in the drive trainof the driving mechanism, the gear ratio of the driving mechanism ischanged so that the speed of the take-up reel is slowed down. Therefore,when the gears 41 and 42 are interposed in the driving mechanism, thetake-up does not wind film as fast as film is fed from the supply andexcess film accummulates in the film cartridge during this portion offilming operation. The excess length of film once exposed, can berewound on the supply for a second exposure of that portion of film.After rewinding of the desired length of film, the take-up transmissionis coupled for normal rate drive to take up film at the same rate asfilm is fed by a not shown shuttle device.

Although I have described a preferred embodiment of the invention inconsiderable detail, it will be understood that the description thereofis intended to be illustrative, as many of the details may be modifiedor changed without departing from the spirit or scope of theinvention.

What is claimed is:

1. In a camera, a drive mechanism for driving a film take-up at the samerate as film is fed thereto and at a rate different from that rate, themechanism comprismg:

means interengageable with said drive mechanism for slowing the rate ofsaid take-up relative to the rate of feed of the film; and

means for moving said first mentioned means into and out of engagementwith said drive mechanism.

2. The drive mechanism recited in claim 1,'in which said first mentionedmeans comprises a co-rotatable gear pair.

3. The drive mechanism recited in claim 2, in which said secondmentioned means comprises a pivoted lever on which said gear pair isrotatably mounted, and a control member for actuating said lever.

4. A drive mechanism as in claim 1, wherein said drive mechanismcomprises a driven gear, a second gear concentric with said driven gearand fixed to a take-up shaft, a friction member interconnecting saidconcentric gears, and said interengaging means comprises a co-rotatablegear pair, and means for meshing said gear pair respectively with saidconcentric gears whereby said second gear is driven by said driven gearindependently of said friction member.

5. A two-speed take-up drive mechanism comprising a shaft engaging thehub of a take-up for rotating same, a first gear fixed to said shaft, asecond gear rotatable relative to said shaft, means for rotating saidsecond gear at a constant speed, a spring washer frictionally engagedwith said first and second gears for rotating said first gear at normalspeed when said second gear is rotated, a lever pivoted in a planeparallel to the planes of said first and second gears, and aco-rotatable gear pair rotatably mounted on said lever, said lever beingoperable to move said gear pair into meshing engagement with said firstand second gears, whereby said second gear drives said first gearthrough said compound gear independently of the frictional engagement ofsaid spring washer.

6. in a camera, a housing accepting a film cartridge having aunidirectionally rotatable take-up means, said tak -u eans h vin a hubext din throu h one wall oi sgd cartri dgq a take-up (i r ive f said c:amera engageable with said hub for rotating said take-up means, thedriving comprising a shaft, a first gear fixed to said shaft, a secondgear rotatably mounted on said shaft, means for driving said second gearat a constant speed, friction means engaging said first and second gearsto drive said first gear in response to the rotation of said secondgear, a co-rotatable gear pair engageable with said first and secondgears for driving said first gear in response to the rotation ofsaidsecond gear independently of said friction means and means formoving said gear pair into and out of engagement with said first andsecond gears.

7. The structure recited in claim 6, in which said last mentioned meanscomprises a pivoted lever on which said gear pair is rotatably mounted,a control means coupled to said lever and having a portion arrangedexternally of said housing for manual actuation and a spring meanssecured to said housing and to said lever to disengage said co-rotatablygear pair from said first and second gears when said control member isreleased.

8. In a camera having motive means for driving a film transport at apredetermined rate and for driving a unidirectionally operable filmtake-up, the improvement comprising:

a two speed transmission between said motive means and said take-up fordriving said take-up at a first rate corresponding to a film transportrate and at a second rate slower than the film transport rate.

1. In a camera, a drive mechanism for driving a film take-up at the samerate as film is fed thereto and at a rate different from that rate, themechanism comprising: means interengageable with said drive mechanismfor slowing the rate of said take-up relative to the rate of feed of thefilm; and means for moving said first mentioned means into and out ofengagement with said drive mechanism.
 2. The drive mechanism recited inclaim 1, in which said first mentioned means comprises a co-rotatablegear pair.
 3. The drive mechanism recited in claim 2, in which saidsecond mentioned means comprises a pivoted lever on which said gear pairis rotatably mounted, and a control member for actuating said lever. 4.A drive mechanism as in claim 1, wherein said drive mechanism comprisesa driven gear, a second gear concentric with said driven gear and fixedto a take-up shaft, a friction member interconnecting said concentricgears, and said interengaging means comprises a co-rotatable gear pair,and means for meshing said gear pair respectively with said concentricgears whereby said second gear is driven by said driven gearindependently of said friction member.
 5. A two-speed take-up drivemechanism comprising a shaft engaging the hub of a take-up for rotatingsame, a first gear fixed to said shaft, a second gear rotatable relativeto said shaft, means for rotating said second gear at a constant speed,a spring washer frictionally engaged with said first and second gearsfor rotating said first gear at normal speed when said second gear isrotated, a lever pivoted in a plane parallel to the planes of said firstand second gears, and a co-rotatable gear pair rotatably mounted on saidlever, said lever being operable to move said gear pair into meshingengagement with said first and second gears, whereby said second geardrives said first gear through said compound gear independently of thefrictional engagement of said spring washer.
 6. In a camera, a housingaccepting a film cartridge having a unidirectionally rotatable take-upmeans, said take-up means having a hub extending through one wall ofsaid cartridge, a take-up drive of said camera engageable with said hubfor rotating said take-up means, the driving comprising a shaft, a firstgear fixed to said shaft, a second gear rotatably mounted on said shaft,means for driving said second gear at a constant speed, friction meansengaging said first and second gears to drive said first gear inresponse to the rotation of said second gear, a co-rotatable gear pairengageable with said first and second gears for driving said first gearin response to the rotation of said second gear independently of saidfriction means and means for moving said gear pair into and out ofengagement with said first and second gears.
 7. The structure recited inclaim 6, in which said last mentioned means comprises a pivoted lever onwhich said gear pair is rotatably mounted, a control means coupled tosaid lever and having a portion arranged externally of said housing formanual actuation and a spring meanS secured to said housing and to saidlever to disengage said co-rotatably gear pair from said first andsecond gears when said control member is released.
 8. In a camera havingmotive means for driving a film transport at a predetermined rate andfor driving a unidirectionally operable film take-up, the improvementcomprising: a two speed transmission between said motive means and saidtake-up for driving said take-up at a first rate corresponding to a filmtransport rate and at a second rate slower than the film transport rate.